AMD Ryzen 9 6900HX 's Advantages
Higher specification of memory (6400 vs 5600)
AMD Ryzen 7 7840H 's Advantages
Released 1 years late
Better graphics card performance
Larger memory bandwidth (89.6GB/s vs 76.8GB/s)
Newer PCIe version (4 vs 4.0)
Higher base frequency (3.8GHz vs 3.3GHz)
More modern manufacturing process (4nm vs 6nm)
Lower TDP (35W vs 45W)